In the prior art, connectors for industrial automation or mobile equipment products are known having a full or partial non-bondable enclosure for receiving one or more electrical conductors to be connected by means of such connectors. The enclosure often serves the purpose of protecting the electrical conductor(s) within the connector from electromagnetic interference and/or physical damage. For protecting the connector and/or the electrical conductor from environmental influences and/or from the intrusion of foreign bodies and/or fluids, in particular from the intrusion of dust and/or moisture, an outside over-molded thermoplastic shell is typically provided. Such a thermoplastic shell can typically not be directly attached to the enclosure, because the enclosures are often made of materials not allowing a bonding with the over-molded thermoplastic shell. Thus, further means are required for hindering the ingress of foreign bodies and/or fluids between the over-molded shell and the enclosure.
Typically, a sealing between the enclosure and the over-mold shell is achieved by producing the connector in a two-step over-mold process, wherein in a first molding step the enclosure is sealed with a glue-like hot melt and in a second step a thermoplastic molding is added to achieve mechanical and chemical protection and also a robust appearance and good haptic properties. A production method for a shielded connector is disclosed, for example, in U.S. Pat. No. 7,976,341 B2. Such an assembly typically allows an ingress protection up to a protection class of IP67.
However, such production methods are challenging due to the use of hot melt adhesives for sealing the enclosure by encapsulation, the success of which is often highly dependent on the molding process parameters making it difficult to achieve the necessary level of control of essential production parameters. In particular when encapsulating assemblies varying in their volume and/or geometry, such as a varying number of electrical conductors in the connector, careful adjustments of manufacturing parameters may be required. Moreover, additional process steps are required, like two-step molding or compression fitting between the components, to achieve proper sealing of the connector, which increase the effort and costs for producing the connectors.
Conventional production methods for shielded connectors often are based on adding adhesives. This labor intensive procedure often leads to varying results due to changing environmental conditions during the production, such as temperature, pressure, humidity etc.
Other conventional methods are based on providing grooves for increased path length of water ingress. Such methods require expensive, custom machined parts. Furthermore, such methods require a distinct orientation of the involved parts during their assembly and the resulting connector is typically bigger than functionally necessary.
Yet other conventional methods involving a two-step molding require two distinct sets of tooling, such as two different kinds of molding machinery, which results in high financial expenses. Moreover, the success of such production methods is typically highly dependent on the careful control of molding parameters within a small range.
Other conventional methods are based on a single compression fit between the components of the connector, which also requires expensive customized components made in tight tolerances. In addition, the assembly often requires special tooling rendering the production method and, thus, the produced connectors expensive.